US4147816A - Method of improving the output and maintenance of a fluorescent lamp - Google Patents
Method of improving the output and maintenance of a fluorescent lamp Download PDFInfo
- Publication number
- US4147816A US4147816A US05/785,463 US78546377A US4147816A US 4147816 A US4147816 A US 4147816A US 78546377 A US78546377 A US 78546377A US 4147816 A US4147816 A US 4147816A
- Authority
- US
- United States
- Prior art keywords
- phosphor
- chloride
- lehring
- lamp
- maintenance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims 5
- 238000012423 maintenance Methods 0.000 title abstract description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 22
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000000725 suspension Substances 0.000 claims abstract description 8
- HMOQPOVBDRFNIU-UHFFFAOYSA-N barium(2+);dioxido(oxo)silane Chemical class [Ba+2].[O-][Si]([O-])=O HMOQPOVBDRFNIU-UHFFFAOYSA-N 0.000 claims abstract description 5
- 235000019270 ammonium chloride Nutrition 0.000 claims abstract description 4
- 239000011248 coating agent Substances 0.000 claims abstract description 4
- 238000000576 coating method Methods 0.000 claims abstract description 4
- 238000004519 manufacturing process Methods 0.000 claims abstract 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 9
- 229910000464 lead oxide Inorganic materials 0.000 claims description 2
- 238000012545 processing Methods 0.000 claims description 2
- 230000015572 biosynthetic process Effects 0.000 claims 1
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 claims 1
- 150000003841 chloride salts Chemical class 0.000 abstract 1
- 238000007792 addition Methods 0.000 description 8
- HTUMBQDCCIXGCV-UHFFFAOYSA-N lead oxide Chemical compound [O-2].[Pb+2] HTUMBQDCCIXGCV-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910017917 NH4 Cl Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- -1 for example Chemical compound 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 229910020489 SiO3 Inorganic materials 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical compound [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 description 1
- 229910001626 barium chloride Inorganic materials 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- HWSZZLVAJGOAAY-UHFFFAOYSA-L lead(II) chloride Chemical compound Cl[Pb]Cl HWSZZLVAJGOAAY-UHFFFAOYSA-L 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel
- H01J9/22—Applying luminescent coatings
- H01J9/221—Applying luminescent coatings in continuous layers
- H01J9/223—Applying luminescent coatings in continuous layers by uniformly dispersing of liquid
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/66—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing germanium, tin or lead
- C09K11/666—Aluminates; Silicates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/38—Devices for influencing the colour or wavelength of the light
- H01J61/42—Devices for influencing the colour or wavelength of the light by transforming the wavelength of the light by luminescence
- H01J61/44—Devices characterised by the luminescent material
Definitions
- This invention concerns fluorescent lamps.
- Such lamps are low pressure mercury arc discharge devices which have electrodes at each end of an elongated glass envelope and which contain a phosphor coating on the inner surface of the glass envelope.
- the invention is particularly concerned with lamps utilizing lead activated barium mesosilicate phosphor. This phosphor is an ultraviolet emitting phosphor peaking at about 351 nanometers.
- the initial output and the maintenance can be significantly improved by adding a heat decomposable or vaporizable chloride, for example, ammonium chloride, to the phosphor coating suspension.
- a heat decomposable or vaporizable chloride for example, ammonium chloride
- the chloride improves lamp performance by eliminating any lead oxide that may occur during lamp processing, particularly during the lehring operation.
- the lead activator in the phosphor has a tendency to become oxidized during the lehring operation and to form a film of yellow PbO on the surface of the phosphor crystals. Although the amount of PbO formed is very small, it is nevertheless sufficient to cause a shift of approximately 3 nanometers in the peak of the emission due to the filtering effect.
- the NH 4 Cl addition according to the invention reacts readily with the PbO to form PbCl 2 which is sufficiently volatile at the lehring temperature of approximately 650° C. to be eliminated from the surface of the phosphor film.
- the barium mesosilicate phosphor can be prepared by conventional methods in which typical raw mix constituents, such as BaCO 3 , H 2 SiO 3 , BaCl 2 and Pb acetate, are mixed together in proportions to satisfy the phosphor formulation corresponding to BaSiO 5 :Pb.sub..03 F.sub..09 and fired in silica crucibles at temperatures ranging from 1000 to 1100° C. for 4 to 8 hours. After cooling, the phosphor is ball-milled in water for 2 hours and filtered to remove the excess water.
- typical raw mix constituents such as BaCO 3 , H 2 SiO 3 , BaCl 2 and Pb acetate
- the wet cake is resuspended in a conventional water-base vehicle to which is added NH 4 Cl in amounts ranging between 0.5 and 5%, and preferably 2% by weight of the dry phosphor.
- the resulting suspension may also include the usual wetting and defoaming agents known in the art and is used to coat the fluorescent bulbs in the conventional manner.
- the bulbs After drying, the bulbs are lehred for approximately 3 minutes at a temperature ranging between about 600° and 650° C. and the lamps are finished in the conventional manner.
- the water suspension was filtered under vacuum and the cake was resuspended in 1000 ml of 5.4% polyoxyethylene vehicle diluted with 300 ml deionized water and containing 2.4 grams of fumed aluminum oxide as adherence promoter.
- the resulting suspension was divided into three equal portions, the first one being used as control. To the other two portions were added respectively 1.35 and 2.7 grams NH 4 Cl corresponding to 1 and 2% by weight of dry phosphor.
- the heat decomposable or vaporizable chloride can comprise an organic chloride which is soluble in the solvent.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Vessels And Coating Films For Discharge Lamps (AREA)
- Luminescent Compositions (AREA)
- Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
Abstract
In the manufacture of a fluorescent lamp having lead activated barium mesosilicate phosphor coated on the inner wall of the lamp envelope, ammonium chloride or other heat decomposable chlorides are added to the phosphor coating suspension in order to improve the initial output and the maintenance of the lamp.
Description
This is a continuation of application Ser. No. 634,959, filed Nov. 24, 1975, now abandoned.
This invention concerns fluorescent lamps. Such lamps are low pressure mercury arc discharge devices which have electrodes at each end of an elongated glass envelope and which contain a phosphor coating on the inner surface of the glass envelope. The invention is particularly concerned with lamps utilizing lead activated barium mesosilicate phosphor. This phosphor is an ultraviolet emitting phosphor peaking at about 351 nanometers.
I have found that in such lamps the initial output and the maintenance can be significantly improved by adding a heat decomposable or vaporizable chloride, for example, ammonium chloride, to the phosphor coating suspension. I believe that the chloride improves lamp performance by eliminating any lead oxide that may occur during lamp processing, particularly during the lehring operation. The lead activator in the phosphor has a tendency to become oxidized during the lehring operation and to form a film of yellow PbO on the surface of the phosphor crystals. Although the amount of PbO formed is very small, it is nevertheless sufficient to cause a shift of approximately 3 nanometers in the peak of the emission due to the filtering effect. The NH4 Cl addition according to the invention reacts readily with the PbO to form PbCl2 which is sufficiently volatile at the lehring temperature of approximately 650° C. to be eliminated from the surface of the phosphor film.
The barium mesosilicate phosphor can be prepared by conventional methods in which typical raw mix constituents, such as BaCO3, H2 SiO3, BaCl2 and Pb acetate, are mixed together in proportions to satisfy the phosphor formulation corresponding to BaSiO5 :Pb.sub..03 F.sub..09 and fired in silica crucibles at temperatures ranging from 1000 to 1100° C. for 4 to 8 hours. After cooling, the phosphor is ball-milled in water for 2 hours and filtered to remove the excess water. The wet cake is resuspended in a conventional water-base vehicle to which is added NH4 Cl in amounts ranging between 0.5 and 5%, and preferably 2% by weight of the dry phosphor. The resulting suspension may also include the usual wetting and defoaming agents known in the art and is used to coat the fluorescent bulbs in the conventional manner.
After drying, the bulbs are lehred for approximately 3 minutes at a temperature ranging between about 600° and 650° C. and the lamps are finished in the conventional manner.
As a specific but non-limitative example according to the invention, 400 grams of lead activated barium mesosilicate phosphor were milled for 2 hours in a pebble mill containing 600 ml of deionized water.
After milling, the water suspension was filtered under vacuum and the cake was resuspended in 1000 ml of 5.4% polyoxyethylene vehicle diluted with 300 ml deionized water and containing 2.4 grams of fumed aluminum oxide as adherence promoter.
The resulting suspension was divided into three equal portions, the first one being used as control. To the other two portions were added respectively 1.35 and 2.7 grams NH4 Cl corresponding to 1 and 2% by weight of dry phosphor.
These suspensions were used to coat fluorescent 4CT12 lamps which gave the following results in relative units of ultraviolet emission:
______________________________________
0 Hour 100 Hours 1000 Hours
______________________________________
Control (no addition)
14.352 11,248 9,213
1% NH.sub.4 Cl Addition
17,052 14,128 10,941
2% NH.sub.4 Cl Addition
17,136 14,660 11,885
______________________________________
It can be seen that the chloride additions increased the initial output from 14,352 to over 17,000, an increase of more than 18%.
A similar test was conducted in 48T12-VHO lamps giving the following values:
______________________________________
1000
Hours
Main-
0 5000 1000 ten-
Hour Hours Hours ance
______________________________________
Control (no addition)
28,125 17,428 13,499 47.8%
2% NH.sub.4 Cl Addition
32,353 24,905 19,705 60.9%
______________________________________
In this test the chloride addition increased initial output by 15% and also increased the 100 hour maintenance by 13%.
When the suspension used to coat the phosphor is organic solvent based, instead of water-base, the heat decomposable or vaporizable chloride can comprise an organic chloride which is soluble in the solvent.
Claims (5)
1. The method of manufacturing a fluorescent lamp comprising the steps of: preparing a lead-activated barium mesosilicate phosphor suspension containing a heat decomposable chloride dissolved therein which can prevent formation of lead oxide during lehring; applying said suspension to the envelope of the lamp in order to deposit a phosphor coating thereon; and processing the phosphor coated envelope into a finished lamp including the step of lehring said phosphor coated envelope.
2. The method of claim 1 wherein said chloride is vaporizable at the lehring temperature.
3. The method of claim 2 wherein said lehring temperature is about 600° to 650° C.
4. The method of claim 2 where said chloride is ammonium chloride.
5. The method of claim 4 wherein the ammonium chloride comprises from about 0.5 to 5% of the weight of the phosphor.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US63495975A | 1975-11-24 | 1975-11-24 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US63495975A Continuation | 1975-11-24 | 1975-11-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US4147816A true US4147816A (en) | 1979-04-03 |
Family
ID=24545838
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US05/785,463 Expired - Lifetime US4147816A (en) | 1975-11-24 | 1977-04-07 | Method of improving the output and maintenance of a fluorescent lamp |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4147816A (en) |
| JP (1) | JPS52101880A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5858277A (en) * | 1992-12-23 | 1999-01-12 | Osram Sylvania Inc. | Aqueous phosphor coating suspension for lamps |
| EP0962514B1 (en) * | 1998-06-04 | 2003-11-26 | Osram Sylvania Inc. | Cation-treated silicate phosphor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2587592A (en) * | 1947-02-01 | 1952-03-04 | Sylvania Electric Prod | Barium mesotrisilicate phosphor |
| US2597631A (en) * | 1950-03-22 | 1952-05-20 | Gen Electric | Method of preparing barium silicate phosphor |
| US3679452A (en) * | 1971-01-28 | 1972-07-25 | Westinghouse Electric Corp | Process for coating lehring-sensitive phosphor onto lamp envelope |
-
1976
- 1976-11-24 JP JP14173076A patent/JPS52101880A/en active Pending
-
1977
- 1977-04-07 US US05/785,463 patent/US4147816A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2587592A (en) * | 1947-02-01 | 1952-03-04 | Sylvania Electric Prod | Barium mesotrisilicate phosphor |
| US2597631A (en) * | 1950-03-22 | 1952-05-20 | Gen Electric | Method of preparing barium silicate phosphor |
| US3679452A (en) * | 1971-01-28 | 1972-07-25 | Westinghouse Electric Corp | Process for coating lehring-sensitive phosphor onto lamp envelope |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5858277A (en) * | 1992-12-23 | 1999-01-12 | Osram Sylvania Inc. | Aqueous phosphor coating suspension for lamps |
| EP0962514B1 (en) * | 1998-06-04 | 2003-11-26 | Osram Sylvania Inc. | Cation-treated silicate phosphor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS52101880A (en) | 1977-08-26 |
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